This invention relates to large water-containing reservoirs and more specifically, it relates to managing a large body of water in a reservoir to ensure high quality water for dispensing to municipalities and the like.
Large water reservoirs have the problem that water at or near the surface can become warmer during the summer, particularly in warm climates. Make-up water usually is colder and, while it may reduce the temperature, is not very effective and instead make-up water can short-circuit the retained water in the reservoir. This has the problem that it leads to poor mixing and temperature gradients accompanied by ineffective mixing of disinfectant chemicals added to the reservoir. Thus, the reservoir retains poor quality water. Accordingly, it will be seen that there is great need for a system which effectively disinfects and maintains uniformity in temperature.
Different systems have been proposed for treating and managing water systems. For example, U.S. Pat. No. 6,245,224 discloses a water quality management system for managing the water quality in a water supply network having water pipe lines running from the purification plant to consumers"" faucets to maintain the water quality at the consumers at the terminals of the network at an appropriate level. The water quality monitors for measuring the quality of water in the pipe lines are installed in the small-pipe water distribution network branching from the water distribution main pipe network and running toward the consumers. The water distribution facility for improving the water quality is installed at the base point of the small-pipe water distribution network. The water quality in the small-pipe water distribution network is managed based on the signals from the water quality monitors.
U.S. Pat. Nos. 3,724,474 and 3,897,798 disclose that the halogen level in a water treatment system is monitored and controlled by a method which includes continuous sensing of the halogen level in a flow of the water under treatment, detecting insufficient halogen levels, adding halogen in response to detection of insufficient halogen levels, and terminating the addition of halogen upon detection of a second halogen level which is above that of the first mentioned level. Apparatus for carrying out this method includes a pair of electrodes disclosed in a stream of the fluid undergoing treatment, a charge storage device connected across the electrodes, means for pulsing electrodes and charged storage device, means for detecting the decay of stored charge as a function of the halogen level of the fluid and means for controlling the addition of halogen in accordance with desired halogen levels.
U.S. Pat. No. 4,094,786 discloses a control apparatus for water treatment systems which embodies a float switch actuably responsive to a predetermined drop in stored water level causing the pumping of treatment solution to a predetermined rate of flow controlled by a flow orifice for a predetermined period of time when called for by a thus energized clock totalizer embodying cam mechanism therein and a sensitive switch responsive thereto for controlling the flow of treatment solution to the water reservoir proportional to the delivery of make up water controlled by the float switch.
U.S. Pat. No. 6,077,444 discloses a method of manufacturing a water treatment system for providing a flow of treated water having a pre-established quality, for example, a maximum TDS and permitted pH range, from a flow of reclaimed water having a quality poorer than the pre-established quality of the treated water and a flow of treatment water. The system includes a mixing reservoir; first and second fluid conduits connected to the mixing reservoir for flowing the reclaimed water and the treatment water into the reservoir; and a third fluid conduit connected to the mixing reservoir for discharging a flow of treated water from the mixing reservoir, and sensors connected for sensing the flow rates and qualities of the reclaimed water and treatment water flowed into the mixing reservoir and of the treated water discharged from the mixing reservoir. Signals, e.g., electrical signals, associated with the sensors indicate the sensed water flow rates and qualities, and controls responsive to the signals regulate the flows of reclaimed water and treatment water into the mixing reservoir through the controlled flow valves in the first and second conduits so as to cause the quality of the treated water discharged from the mixing reservoir through said third fluid conduit to be at least about as good as the pre-established treated water quality.
In spite of these disclosures, there is still a great need for an improved method and system for managing or controlling a large body of water contained in a reservoir to ensure uniformity of temperature within the reservoir and to ensure high quality of water for dispensing therefrom.
It is an object of the invention to provide an improved water reservoir system.
It is another object of the invention to provide an improved treatment system for a body of water contained in a reservoir.
Yet, it is another object of the invention to remove temperature stratification or gradients and provide for temperature uniformity in large water-containing reservoir.
Still, it is another object of the invention to provide for continuous chlorine or chlorine-related analysis of water and automatically and continuously control dosage of chemicals added to the water to maintain high quality municipal usable water.
These and other objects will become apparent from a reading of the specification and claims and an inspection of the drawings appended hereto.
In accordance with these objects, there is provided a method for controlling water impurity level and temperature uniformity within large water-containing reservoirs, the method having the ability to deliver chemically-treated water from said reservoir to the end user. The method comprises providing a reservoir having a body of water therein and locating a recirculating pump in the body of water, the pump ejecting a jet of water therefrom and ingesting water at a point remote or away from said ejecting. An eductor is placed in the jet of water, pulling in low pressure water to the eductor and flowing a stream of water therefrom, providing mixing and circulation of water within the reservoir and removing temperature gradient in the body of water. One of ammonia and a hypochlorite is added to the body of water on a continuous basis, the ammonia or hypochlorite is added to the stream of water flowing from the eductor to ensure against concentration gradients. Simultaneously with the mixing, a test stream of water is removed from the reservoir on a continuous basis. The level of at least one of chlorine and chloroamine in the test stream is determined to provide a chlorine or chloroamine measurement related signal which is relayed to a controller. In the controller, the signal is compared to a set point indicative of the level of chlorine or chloroamine desired in the water in the reservoir to provide a comparison. In response to the comparison, the amount of ammonia or hypochlorite being added to the reservoir is maintained, increased or decreased to provide the quality of water desired in the reservoir.
Additionally, there is provided a system for managing water purity level and water temperature uniformity within large water-containing reservoirs, the system having the ability to provide chemically-treated water having uniform temperature for end users. The system is comprised of a recirculating pump for locating in a body of water in a reservoir, the pump designed to produce a jet of water therefrom in the body and to ingest water from the body at a point remote from the ejecting. An eductor is positioned in the jet of water, the eductor designed to draw low pressure water surrounding the eductor and to discharge a stream of water therefrom to provide further mixing and circulation of water within the reservoir and to remove or destroy temperature gradients in the body of water while maintaining uniform disinfectant levels. Means are provided for adding at least one of ammonia and hypochlorite or other chemicals to the body of water on a continuous basis, the means designed to add one of the ammonia and hypochlorite, for example, to the stream of water discharging from the eductor. Further, means are provided for removing a test stream of water from the reservoir on a continuous basis, the means designed to remove the test stream remote from the water discharging from the eductor. An analyzer is used for determining the level of at least one of chlorine and chloroamine or other chemical in the test stream to provide a chlorine or chloroamine or chemical related signal. A controller is designed to receive the signal and to compare the signal to a set point indicative of the level of chlorine, chloroamine, or other chemical, desired in the reservoir water to provide a comparison, and in response to the comparison, the controller is designed to maintain, increase, or decrease the amount of ammonia or hypochlorite added to the body of water in the reservoir to provide high quality water for the end users.